twist needed for .308" 240g SMK's??

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by cowboy717, Jun 3, 2008.

  1. cowboy717

    cowboy717 Well-Known Member

    Messages:
    160
    Joined:
    Apr 17, 2008
    hey, i am now the prowd new owner of a custom 300 ultra mag, was looking for a gun to build a 338 edge but this kinda just jumped out at me, it is a remington 700 action, h-s precision stock w/ adjustable cheekpad and LOP. and a 30" stainless barrel with a muzzle brake.
    i'm wonderin what twist is needed for these heavy bullets, i'm in the process of tryin to figure out the twist in the barrel but my dewey rod is bein a pain.
    i would like to try sierras 240 if at all possible, but may settle for any in the 200-220 range
    also wonderin what kinda loads should i try in it?? its my first experience with a big 300, other than a 300 win that wouldn't shoot baseballs at 100 yds.
    thanks
    also shoppin for a scope and rings/base as i speak!!! any advice is appreciated, i'm a novice at long range,,,, 500 is about as far as i've shot.. but really wanna shoot at 1000+ what do i need to get started??
     
  2. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004
    Cowboy

    Most custom 30 cal barrels have a 1 in 10 twist, If so then it will be fine for
    240's in the big RUM.

    As far as scopes I would recomend a tactical with side focus,30mm tube,
    50mm objective and 4 to 6x 14 to 20 power.

    The brand would be determined by how much money you are willing to spend.

    J E CUSTOM
     

  3. P KUNDA

    P KUNDA Well-Known Member

    Messages:
    121
    Joined:
    Feb 2, 2008
    240SMK 1:10" twist

    Peter
     
  4. jmden

    jmden Well-Known Member

    Messages:
    2,725
    Joined:
    Nov 2, 2003
    1 in 10 will stabilize the 240 at 300RUM velocities. However, Sierra says to use 1 in 9 for the big 240. I'm shooting 104.5g US869 at 3K MV with the 240 resting on the lands. This is a cold weather load. At least 60F or below. 4-6 firings. Good luck.
     
  5. Lightvarmint

    Lightvarmint Guest

    Hello,

    It really depends on air density and bullet speed.

    james
     
  6. Mr. Reaper

    Mr. Reaper Member

    Messages:
    9
    Joined:
    May 13, 2006
    Twist Rate

    1:10" for the 240 SMK in .308 cal, even at this altitude.